Device for cutting and inserting locking elements into threaded fasteners



1965 c. R. BEUTER ETAL 3,

DEVICE FOR CUTTING AND INSERTING LOCKING E ENTS INTO THREADED FASTENERS*lginal Filed Feb. 27, 1961 FIGS.

FIG.4.

' INVEN CLYDE R BE JOHN W BRl TORS:

I UTER |2 BY GHTMAN M. M.

THEIR ATTORNEYS United States Patent DEVICE FOR CUTTING AND INSERTINGLOCK- ING ELEMENTS INTO THREADED FASTENERS Clyde R. Beuter, BeverlyHills, Mich., and John W.

Brightman, Ridgewood, N.J., assignors, by mesne assignments, to UnitedShoe Machinery Corporation, Boston, Mass, a corporation of New JerseyOriginal application Feb. 27, 1961, Ser. No. 91,811. Di-

vided and this application Sept. 26, 1963, Ser. No.

3 Claims. (Cl. 18-1) This application is a division of our US.application, Serial No. 91,811, filed February 27, 1961, and nowabandoned.

invention relates to apparatus for cutting and inserting lockingelements in self-locking threaded devices such as, for example,self-locking bolts, machine screws, threaded inserts and the like.

Nuts, bolts, screws and the like have been provided with resilientinserts in one side thereof to produce the locking action described moreparticularly in the Boots US. Patent No. 2,539,887. In some self-lockingscrews and bolts, a strip of resilient material, such as nylon (highmolecular weight synthetic linear polyamide) or its equivalent ispositioned in a groove extending lengthwise of the threaded portion ofthe belt or screw. in order to facilitate application of a nut to such abolt, one end of the strip may be chamt'ered or tapered so that thethreads of the cooperating nut will pass readily over the insert withoutdislodging it. In the formation of such inserts, the opposite end of theinsert is complementally beveled or chamt'ered so that the strip has aprojecting tip which sometimes catches on other elements and causes thestrip to be dislodged from the groove thereby rendering the threadeddevice defective.

In accordance with the present invention, apparatus is provided forcutting inserts from plastic filaments or rods in such a way that theinserts have oppositely inclined ends which are free from prog'ectingtips or points.

More particularly, the apparatus for forming the looking strips includesa blade having wedge-shaped cutting portions at its ends which formcharnfered ends on inserts severed from a rod or strip of resilientmaterial, compresses the insert by forcing it through a narrow ejectionslot and inserts the strip in a groove formed in the threaded device.Upon expansion of the insert in the groove due to the inherentresiliency of the insert it will engage tightly in and resistdislodgment from the groove.

Inasmuch as the resilient inserts are not readily dislodged :irom thescrews, bolts or the like, fewer defective articles will be producedthan heretofore.

For a better understanding of the present invention, reference may behad to the accompanying drawing in which:

FIGURE 1 is a side elevational view of a typical self locking screwproduced with apparatus embodying the present invention;

FIGURE 2 is a slightly enlarged view taken on line 22 of FIGURE 1;

FIGURE 3 is a view in section on line 33 of FIG- UR E-Z;

FIGURE 4 is a side elevational view of an apparatus embodying thepresent invention for cutting and inserting the locking strips in screwsand the like; and

FIGURE 5 is a view in cross section taken on line 5-5 of FIGURE 4.

As shown in FIGURES 1 to 3, a threaded machine screw is chosen toillustrate the invention. *It will be understood, however, that otherthreaded devices such as bolts, screw threaded inserts, nuts, and thelike may be 3,203,041 Patented Aug. 31, 1965 provided with lockinginserts of the type produced with apparatus embodying the present invention.

The machine screw '10 includes the usual hex head 11 and threaded shank12 in which is formed, by a milling or other operation, a groove orrecess 13 which intersects a plurality of the threads of the shank andhas an open end at the end of the screw shank. Mounted within the grooveor recess 13 is a strip 14 of resilient locking material such as nylonwhich is initially of circular cross section but has been compressedduring its insertion into the groove to a non-circular cross section sothat it fits within the groove. Expansion of the insert causes it to befirmly seated in, and gripped by the walls of, the groove. It alsobulges out slightly as at 15 (FIG- URE 3) between the threads of thescrew. As illustrated, the outer surface of the insert 14 extends aboutto the crest line of the threads. It may be disposed between the crestline and the root line of the thread or may project slightly beyond thecrest line.

In order to avoid dislodging the strip 14 from the groove, its oppositeends are provided with outwardly converging beveled or chamlfered faces16 and 17. The face 16 due to its rearward inclination facilitates theinsertion of the screw into a nut or other complementally threaded hole.The opposite chamfered end 17 does not present any projections orcorners which might be engaged by other associated elements and therebycause the insert to be dislodged from the screw during shipment and thelike.

The inserts 14 may be towed and inserted readily in screws and the likeby means of the apparatus according to the invention shown in FIGURES 4and 5. It includes a main housing 20 having a pair of side plates 21 and22 secured by means of socket head screws 23, 24 to narrow front andback plates 25 and 26. A support or fixture F in which the screw 10 isinserted is disposed below the housing 20.

A cutter 27 is mounted in the housing between the plates 21, 22 and 25,26 and is reciprocated by means of a suitable reciprocating slide (notshown) in the head H of the machine. As shown in FIGURES 4 and 5, thecutter 27 has a thin blade portion 28 at its lower end having downwardlyextending wedge-shaped points 29 and 30 at the opposite ends of itslower edge 31.

During reciprocation of the blade 27, it traverses a bore 33 whichextends through the side plates 21 and 22 and recieves a filament or rodN of resilient material from which the inserts are out. As shownparticularly in FIG- URE 4, the diameters of the filament N and the bore33 are greater than the width or thickness of the blade portion 28.Accordingly, when the cutter 27 is forced downwardly, the filament issheared and the insert 14 cut therefrom is forced downwardly through thedischarge slot 35 which fits the. blade and is compressed therein priorto its insertion into the groove 13 in the screw. The blade 28 thus cutsan insert of a desired length from a continuous filament, compresses theends of the insert and forces it through the discharge slot 35 therebycompressing it and forcing it into groove 13 in the screw. Thetransverse compression of the severed strip as it passes through theslot 35 together with the wedging of the ends of the strip by the points29 and 30 of the blade permanently deforms the strip so that it ischanged from circular to a more flattened cross-section and also causesthe ends of the strip to become inclined or cham'fered. The strip willrecover somewhat but will not tend to return to its initially circularcross-section, even if uncon fined. Inasmuch as the groove 16 is aboutthe same width as the slot 35 slight expansion of the insert anchors itsecurely in the groove.

It will be understood that the diameter of the insert will dependlargely upon the size of the threaded device in which it is used, Thelength of the insert also may vary depending upon requirements.Accordingly, the example of the invention given herein should beconsidered as illustrative and not as limiting the scope of thefollowing claims.

We claim:

1. Apparatus vfor cutting locking strips for threaded mernberscomprising a hollow housing having an elongated slit extendingtransversely of one end thereof, and connecting with the interior ofsaid housing, a bore extending transversely of said housing andlengthwise of said slit bewteen its inner and outer ends, said borebeing of greater diameter than said slit to receive a plastic filamentof greater cross-sectional width than said slit, and a blade in saidhousing and reoiprocable in said slit transversely of said bore forcutting a section from said filament substantially equal in length tothe length of said slit, forcing said section through said slit tocompress said sec-tion transversely and ejecting it from said housingthrough said slit.

2. A device for cutting resilient inserts fior self-locking threadeddevices comprising a hollow housing having one open end and an oppositeend with a narrow slit therein, a plunger slidably mounted in saidhousing having a thin blade thereon substantially complemental to saidslit and movable with said plunge-r between a position retracted withinsaid housing to a position projected from said slit, a hole extendingtnansversely of said housing and lengthwise of said slit between itsinner and outer ends for receiving a resilient filament of greater widththan the width of said slit, and means for sliding said plungerlengthwise of said housing to sever a section of said filament, compresssaid section transversely in said slit and eject said section from saidhousing through said slit.

3. The device set forth in claim 2 comprising a shearing edge on the endof said blade having wedge-shaped points at opposite ends of said edgefor ch-arnfering the ends of said section of filament severed by saidblade.

References Cited by the Examiner UNITED STATES PATENTS 1,396,090 11/21Bartlett 18-1 1,739,790 =1 2/29 Glaxner 1-81 1,960,881 5/34 Sunbury18--1 2,289,787 7/42 Kaschke et a1. 18-12 XR FOREIGN PATENTS 84,69710/59 Canada.

WILLIAM J. STEPHENSON, Primary Examiner.

1. APPARATUS FOR CUTTING LOCKING STRIPS FOR THREADED MEMBERS COMPRISINGA HOLLOW HOUSING HAVING AN ELONGATED SLIT EXTENDING TRANSVERSELY OF ONEEND THEREOF, AND CONNECTING WITH THE INTERIOR OF SAID HOUSING, A BOREEXTENDING TRANSVERSELY OF SAID HOUSING AND LENGTHWISE OF SAID SLITBETWEEN ITS INNER AND OUTER ENDS, SAID BORE BEING OF GREATER DIAMETERTHAN SAID SLIT TO RECEIVE A PLASTIC FILAMENT OF GREATER CROSS-SECTIONALWIDTH THAN SAID SLIT, AND A BLADE IN SAID HOUSING AND RECIPROCABLE INSAID SLIT TRANSVERSELY OF SAID BORE FOR CUTTING A SECTION FROM SAIDFILAMENT SUBSTANTIALLY EQUAL IN LENGTH TO THE LENGTH OF SAID SLIT,FORCING SAID SECTION THROUGH SAID SLIT TO COMPRESS SAID SECTIONTRANSVERSELY AND EJECTING IT FROM SAID HOUSING THROUGH SAID SLIT.